Supplementary Material for: Rosai-Dorfman Disease Case Report

Rosai-Dorfman Disease is a rare histiocytic disorder that is characterized by the accumulation of histiocytes in various tissues, most commonly the lymph nodes. Cutaneous RDD is a rare presentation, accounting for less than 10% of all RDD cases. We are reporting a cutaneous Rosai-Dorfman Disease clinically presented for the first time with a dome-like lesion over an indurated plaque in an 18-year-old female. Both lesions were biopsied, and findings suggested Rosai-Dorfman Disease. The patient was referred to an Oncologist with a subsequent PET scan showing hypermetabolic subcutaneous uptake on bilateral thighs and bilateral lumbar lesions, likely corresponding to the patient’s biopsy-proven histiocytosis in addition to a diffuse increased tracer uptake in the thoracic aorta and atria. A clinician should have a high degree of suspicion when two morphologies present in proximity to rule out a single pathological process. This case is unique because of the rarity of the condition as well as the clinical presentation of two different morphologies of an indurated plaque and a dome-like lesion on the same area of the body.